双主序(MS)双星的统计性质对于双星演化和双星族群合成非常重要。为了获得这些性质,我们需要识别这些 MS 双星。在本文中,我们开发了一种方法,利用机器学习从中国空间站望远镜(CSST)巡天中区分单 MS 恒星和双 MS 双星。该方法在识别质量比在 0.20 到 0.80 之间的双星时可靠且高效,且不依赖于质量比分布。但由于对质量比小于 0.20 或大于 0.80 的双星探测效率较低,用该方法识别出的双星数量不能很好地近似原始样本中的双星数量。因此,我们利用该方法的探测效率和经验质量比分布改进了这一点,进而可以推断样本中的双星比例。一旦 CSST 数据可用,我们就可以用训练好的多层感知机模型识别 MS 双星,并推导样本的双星比例。
英文摘要:
The statistical properties of double main sequence (MS) binaries are very important for binary evolution and binary population synthesis. To obtain these properties, we need to identify these MS binaries. In this paper, we have developed a method to differentiate single MS stars from double MS binaries from the Chinese Space Station Telescope (CSST) Survey with machine learning. This method is reliable and efficient to identify binaries with mass ratios between 0.20 and 0.80, which is independent of the mass ratio distribution. But the number of binaries identified with this method is not a good approximation to the number of binaries in the original sample due to the low detection efficiency of binaries with mass ratios smaller than 0.20 or larger than 0.80. Therefore, we have improved this point by using the detection efficiencies of our method and an empirical mass ratio distribution and then can infer the binary fraction in the sample. Once the CSST data are available, we can identify MS binaries with our trained multi-layer perceptron model and derive the binary fraction of the sample.
The Chinese Space Station Telescope (CSST) spectroscopic survey plans to deliver high-quality low-resolution ($R > 200$) slitless spectra for hundreds of millions of targets down to a limiting magnitude of about 21 mag, covering a large survey area (17500 deg$^2$) and a wide wavelength range (255-1000 nm by 3 bands GU, GV, and GI). In this work, we use empirical spectra of the Next Generation Spectral Library to simulate the CSST stellar spectra at $R = 250$, and investigate their capabilities in measuring radial velocities. We find that velocity uncertainties depend strongly on effective temp…
The Chinese Space Station Telescope (CSST) spectroscopic survey aims to deliver high-quality low-resolution ($R > 200$) slitless spectra for hundreds of millions of targets down to a limiting magnitude of about 21 mag, distributed within a large survey area (17500 deg$^2$) and covering a wide wavelength range (255-1000 nm by 3 bands GU, GV, and GI). As slitless spectroscopy precludes the usage of wavelength calibration lamps, wavelength calibration is one of the most challenging issues in the reduction of slitless spectra, yet it plays a key role in measuring precise radial velocities of stars…
Constraining Dark Matter Density Profiles in UFDs with Wide Binaries: Forecast for the Chinese Space Station Survey Telescope
School of Science, Hangzhou Dianzi University(杭州电子科技大学理学院);National Astronomical Data Center Zhejiang Branch(国家天文台浙江分中心);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);Institute for Astronomy, University of Edinburgh(爱丁堡大学天体物理研究所)
Multiple populations detection with the Chinese Space Station Survey Telescope main survey camera
School of Physics and Astronomy, Sun Yat-sen University(中山大学物理学院);CSST Science Center for the Guangdong-Hong Kong-Macau Greater Bay Area(中国空间站巡天望远镜大湾区科学中心);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University(北京师范大学天文与前沿科学研究院);Osservatorio Astronomico di Padova(帕多瓦天文台);Dipartimento di Fisica e Astronomia “Galileo Galilei”, Univ. di Padova(帕多瓦大学伽利略物理学与天文学系)
JW-ASTClaw: A Generalizable Multi-Agent Framework for Autonomous Solar Telescope and Its Implementation within Chinese Meridian Project
National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);State Key Laboratory of Solar Activity and Space Weather, National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台太阳活动与空间天气国家重点实验室);University of Chinese Academy of Sciences(中国科学院大学)
This work studies the significance of the lightcurve intrinsic variability in the numerical modeling of contact binaries. Using synthetic light curves we are showing that the starspot-based intrinsic variability increases the apparent mass ratio by $Δq=5$%. For systems with orbital period $P>0.3 d$ the effect of intrinsic variability averaged over long time cancels each other out with the Kepler Mission-like phase smearing. Further, we analyse 47 totally eclipsing Kepler Mission contact binaries. We found a sharp cutoff of the intrinsic variability at P = 0.45 d. With the light curve numerical…
We study the orbital stability of a non-zero mass, close-in circular orbit planet around an eccentric orbit binary for various initial values of the binary eccentricity, binary mass fraction, planet mass, planet semi--major axis, and planet inclination by means of numerical simulations that cover $5 \times 10^4$ binary orbits. For small binary eccentricity, the stable orbits that extend closest to the binary (most stable orbits) are nearly retrograde and circulating. For high binary eccentricity, the most stable orbits are highly inclined and librate near the so-called generalised polar orbit …
A pilot study on the CSST astrometric capability: Detecting astrometric binaries with Gaia synergy via simulated data
Shanghai Astronomical Observatory, Chinese Academy of Sciences(中国科学院上海天文台);School of Astronomy and Space Sciences, University of Chinese Academy of Sciences(中国科学院大学天文与空间科学学院)
Supergiant X-ray Binaries (SgXB) host a compact object, often a neutron star (NS), orbiting an evolved O/B star. Mass transfer proceeds through the intense line-driven wind of the stellar donor, a fraction of which is captured by the gravitational field of the NS. The subsequent accretion process onto the NS is responsible for the abundant X-ray emission from SgXB. They also display peak-to-peak variability of the X-ray flux by a factor of a few 10 to 100, along with changes in the hardness ratios possibly due to varying absorption along the line-of-sight. We use recent radiation-hydrodynamic …
We carry out a numerical experiment of ejecting winds in a massive colliding wind binary system, and quantifying the accretion onto the secondary star under different primary mass loss rates. We set a binary system comprising a Luminous Blue Variable (LBV) as the primary and a Wolf-Rayet (WR) star as the secondary, and vary the mass loss rate of the LBV to obtain different values of wind momentum ratio $η$. Our simulations include two sets of cases: one where the stars are stationary, and one that includes the orbital motion. As $η$ decreases the colliding wind structure moves closer to the se…
This paper presents new trigonometric parallaxes and proper motions for 214 stars. The measurements were made at the US Naval Observatory Flagstaff Station (NOFS) between 1989 and 2017, and the average uncertainty in the parallax values is 0.6 mas. We find good agreement with Gaia Data Release 2 measurements for the stars in common, although there may be a small systematic offset similar to what has been found by other investigators. The sample is matched to catalogs and the literature to create a photometric dataset which spans the ultraviolet to the mid-infrared. New mid-infrared photometry …